In dot-matrix printers, the firing of the wires to register corresponding marks on paper is usually done on the fly, in other words, while the printhead is moving. The printhead, therefore, can completely traverse the width of the paper and print the desired dot pattern at each of a plurality of evenly spaced positions as it traverses the paper without ever stopping. The printhead is usually subjected to selective energization at regular time intervals in order to fire the wires and thus register dots at the selected positions on the paper. It has been the practice to accelerate the carriage before printing is begun and to stop printing before the carriage is decelerated at the end of its travel. Such practices have been necessary in order not to introduce decreased spacing between consecutive printing positions in the accelerating or decelerating areas of the traverse.
In industrial type recorders the width of the chart paper must be kept to a maximum in order to have a maximum resolution in the record. Since the width of the recorder case is limited to the standard rack dimensions typical for industrial mounting, the maximum chart width which is usable for recording is determined in part by the extent of the accelerating and decelerating regions at the beginning and end, respectively, of each traverse unless a means can be found to print in those regions.
It is an object of this invention to provide a method and means for printing with a dot-matrix printer in both the accelerating and decelerating regions of the printhead traverse in order to maximize the width of the printed record for any particular width for the case housing the printer or recorder.